When fitness is talked about, people often think of the body or the physical aspect of it. The fact that the mind needs to be in tip top shape as well becomes forgotten. Getting your mind into good condition is similar to preparing yourself to a marathon. You need to prepare yourself and exercise your mind to get the best results.
Stop multitasking. Multi-tasking doesn't solve problems or complete tasks in less time. It creates such an impression but in reality it only makes things worst. For example, poor or low quality output often result from multi-tasking. Focus on one task at a time. This allows your mind to work better. Your concentration skills will improve as well.
Always think positive. Positive affirmation increases mental proficiency. It strengthens neural pathways to bring your self-confidence, wellbeing, and satisfaction to a higher level. If you talk to yourself negatively, you're most likely to achieve nothing.
Create new experiences. Trying things which are new to you also improves mental fitness. New things exercise your minds to work differently and break away from the patterns which have been established in your brain for a long time. This is a great way to improve your problem solving skills.
Any kind of game that employs the use of logic or reasoning will help you in this area.
Here's some music that can relax your mind.